UNIT 2: NUTRITION

Nutrients: vitamins and minerals that help our body grow.

NUTRITION

DIGESTIVE SYSTEM

CIRCULATORY SYSTEM

RESPIRATORY SYSTEM EXCRETORY

SYSTEM

The digestive system: group of organs that extract nutrients from food and expel waste.PROCESS:1- First, we crush food with teeth and saliva in our

mouth→Bolus.2-Then, we swallow it through our oesophagus.3- Our stomach breaks down food together gastric juices.4- Now, the food is liquid and passes into the small

intestine. Bile (liver) and pancreatic juices broke down into vitamins, minerals, fats and carbohydrates. Nutrients → blood.

5- Finally, the large intestine sends keeps the waste and expels it through the anus.

The digestive system

Key words and their definitions• Nutrients: vitamins and minerals that help your body

grow.

• Saliva: digestive fluids produced into the mouth.• Oesophagus: a tube that joints the mouth with the

stomach.• Stomach: an organ in the digestive system that breaks

down food.• Liver: organ which produces bile.• Bile: a digestive juice that breaks down fat.

Key words and their definitions• Gastric juices: liquid produced by the stomach that

aides in breaking down food.• Small intestine: long and narrow tube that breaks down

and absorbs food.• Large intestine: large tube that removes water from

undigested food and keep the waste.• Anus: end of the large intestine.

• Can you add more key words?

The circulatory system:delivers blood to our body through blood vessels. Its main organ is the heart.

• PROCESS: blood flows around the body in a double circuit.

• 1- Pulmonary circulation: blood flows from the heart to the lungs and back to the heart again.

• 2- Systemic circulation: blood flows from the heart to the rest of the body.

THE HEART: the motor of our body.

• It is divided into 4 chambers:- The 2 on the top are the atria. - The 2 at the bottom are the ventricles.They are separated by valves.

VESSELS: they carry blood through our body

• There are 3 types of vessels:1- Arteries carry blood from the heart to the

rest of the body. They contain oxygen.2- Veins carry the blood back to the heart.

They contain carbon dioxide.3- Capillaries are tiny vessels that connect

arteries and veins.

• The respiratory system helps us to obtain the oxygen and expell the carbon dioxide.

THE RESPIRATION: Main organs are the lungs.First, the air, is inhaled. Then, the trachea, or windpipe, filters the air. The trachea branches into two bronchi, tubes that lead to the lungs. Once in the lungs, oxygen is moved into the bloodstream. Blood carries the oxygen through the body. Red blood cells collect carbon dioxide from the body’s cells and transports it back to the lungs. An exchange of oxygen and carbon dioxide takes place in the alveoli, small structures within the lungs. The carbon dioxide,, is exhaled and the cycle begins again with the next breath.

The excretory system eliminates waste products (carbon dioxide, urine and water) from our body.

It consists of the urinary system and the sweat glands.• Urinary system: the body gets rid of waste from blood.

The main organs are the kidneys.

PROCESS: renal arteries carry blood to the kidneys that filter waste and water and form the urine.

Then the urine leaves the kidneys and passes through the ureters to the bladder which is emptied by the urethra.

• Sweat glands: structures of the skin that produce sweat (a mixture of water and minerals).

These glands excrete the sweat and helps us to regulate the temperature of our body.

The sweat leaves our skin  through tiny holes called pores.